P0477
Exhaust Pressure Control Valve A Low
Exhaust pressure control valve A drive line stuck low — short to ground.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Short to groundCommon
Parts involved
- Exhaust Pressure Regulator
P0477 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.